Heart murmurs

In addition to tones, with auscultation of the heart, additional sounds of longer duration are often heard, which are called noise. Noises of the heart are sound fluctuations, which most often occur in the heart when blood passes through narrowed orifices. The presence of a narrower opening than the norm can be explained by the following reasons:

1. Valves valves are soldered, in connection with which their incomplete opening occurs, ie stenosis - narrowing of the valve opening;
2. a reduction in the surface of the valve flaps or expansion of the valve opening, which leads to incomplete closure of the corresponding opening and a reverse flow of blood through the narrowed space.

In addition, the heart can have abnormal openings, for example, between the ventricles. In all these cases there is a rapid flow of blood through a narrow space.

This causes eddy currents of blood and oscillations of the valves, which spread and are heard on the surface of the chest. In addition to these so-called intracardiac murmurs, non-cardiac sounds are sometimes associated with changes in the pericardium and the pleura that come into contact with it - so-called extracardiac murmurs.

By the nature (timbre) of noise can be blowing, scraping, sawing, etc. In addition, one should keep in mind the noises of a higher frequency - musical.

Noises in the heart always refer to a certain phase of the heart cycle. In this connection, systolic and diastolic noises are singled out.

Systolic heart murmurs

Systolic murmurs are heard after I tone (between I and II tone) and arise due to the fact that during the contraction of the ventricle, blood is expelled from it through the narrowed orifice, while narrowing the lumen of the opening may be in the path of natural blood movement (for example, stenosis of the mouth aorta, or pulmonary artery) or when the blood moves in the opposite direction to the main blood flow (regurgitation), which occurs when the mitral valve is deficient.

Systolic noise is usually more intense at the very beginning, and then they become weaker.

Diastolic murmurs are heard after the 2nd tone (between II and I tone) and are determined in the case when the blood enters the ventricles through the narrowed valvular apertures during the diastole period. The most typical example is stenosis of the left atrioventricular orifice. Diastolic murmur is also heard when the aortic valve is inadequate, when the blood passes through the incompletely closed aperture aperture opening back into the left ventricle.

To determine the nature of valvular defect, the localization of noise is of great importance, as can be seen from the examples mentioned.

In this case, the noise is heard especially well at the same points, in which the tones formed in the corresponding valves or parts of the heart are also listened.

Auscultation of noises arising in the mitral valve region, both in its insufficiency (systolic murmur) and stenosis of the atrioventricular orifice (diastolic murmur) is performed at the apex of the heart.

Listening to the noise arising in the area of the tricuspid valve is made over the lower end of the sternum.

Auscultation of noise, which depends on the change in the aortic valve, is made in the second intercostal space on the right side of the sternum margin. It usually determines the gross systolic noise associated with the narrowing of the aortic orifice, and diastolic noise with aortic valve insufficiency.

Listening to the noise associated with fluctuations in the valve of the pulmonary artery is carried out in the second intercostal space to the left near the edge of the sternum. These noises are similar to aortic.

Noises in the heart are heard not only in these areas, but in a larger space of the heart area. Usually they are well spent on blood flow. Thus, when the aortic orifice narrows, the systolic murmur also spreads to large vessels, for example, the neck. If the aortic valve is insufficient, diastolic noise is determined not only in the second intercostal space on the right, but also on the left in the third intercostal space near the edge of the sternum, at the so-called V point, in the absence of the mitral valve, systolic murmur can be performed in the left axillary region.

The noise, depending on their intensity, is divided into 6 degrees of loudness:

• 1st is a barely audible noise that can at times fade;
• 2nd - more loud noise, constantly determined in the heart;
• 3rd - even more loud noise, but without trembling of the chest wall;
• 4th - loud noise, usually with a trembling of the chest wall, also heard through the palm resting on the chest in the appropriate place;
• 5th - very loud noise, heard not only over the heart area, but at any point of the chest;
• 6th - very loud noise, heard from the surface of the body outside the chest, for example from the shoulder.

Among systolic murmurs, the following are distinguished: ejection noise, pansystolic murmur and late systolic murmur.

Systolic ejection noise occurs as a result of blood flow through the narrowed aortic or pulmonary apertures, and also as a result of acceleration of blood flow through the same unaltered orifices. Noise usually increases to the middle of the systole, then decreases and stops shortly before the second tone. The noise can be preceded by a systolic tone. If the aortic stenosis is expressed, and the contractile function of the left ventricle is preserved, the noise is usually rough in its timbre, loud, accompanied by systolic trembling. It is carried out on the carotid arteries. If heart failure occurs, noise can be significantly reduced and become softer in timbre. Sometimes it is well audible at the top of the heart, where it can be even louder than at the base of the heart.

With stenosis of the pulmonary artery, systolic ejection noise is close to noise in aortic stenosis, but is better heard in the second intercostal space on the left. Noise is carried out in the left shoulder.

With an atrial septal defect, increased blood flow as a result of an overflow of the right side of the heart can lead to systolic ejection on the pulmonary artery, but not more than the third degree of loudness. At the same time, the blood flow through the defect itself usually does not cause noise.

Pansystolic murmurs are named so due to their long duration throughout the systole. This noise usually has a slight gain in the middle or in the first half of the systole. It usually begins with I tone. An example of such noise is the auscultatory pattern with mitral insufficiency. With her at the top of the heart, a pansystolic murmur is heard, which is carried out in the axillary region, reaching the 5th degree of loudness.

If the tricuspid valve is insufficient, pansystolic murmur is usually heard, it is heard better over the right ventricle of the heart at the left edge of the sternum in the fourth intercostal space.

If the defect of the interventricular septum appears systolic noise of great duration at the left edge of the sternum due to a discharge of blood from left to right. Usually it is very rough in its timbre and is accompanied by systolic trembling.

Late systolic noises occur in the second half of the systole. Such noises are observed primarily in the prolapse of the mitral valve. In this condition, elongation or rupture of chords occurs, which leads to the prolapse of mitral valve flaps and mitral insufficiency with the return of blood to the left atrium. The prolapse itself manifests itself in a systolic tone in the middle of the systole and mitral insufficiency with systolic murmur after this tone.

Diastolic heart murmurs 

Diastolic murmurs can be early, appearing after II tone; mesodiastolic and late diastolic, or presystolic.

With aortic insufficiency arises early diastolic murmur of varying intensity in the second intercostal space on the right and at the V point. With a weak diastolic noise, it can sometimes be heard only when the breath is held in exhalation, in the patient's position with a forward tilt.

If the valve of the pulmonary artery, which occurs when it significantly enlarges as a result of pulmonary hypertension, diastolic murmur in the second intercostal space on the left is heard, which is called Steele's noise.

Mitral stenosis in typical cases is manifested by diastolic murmur, best heard at the apex. A characteristic manifestation of this defect is presystolic murmur at the apex, resulting from the systole of the left atrium.

Prolonged noise occurs with arterio-venous fistula, they are heard both in systole and in diastole. Such noise occurs when the arterial (botallova) duct is not inflated. It is most pronounced in the second intercostal space on the left and is usually accompanied by trembling. The noise of friction of the pericardium is heeded by inflammatory changes in its leaflets. This noise is defined as more loud, does not correspond to a strictly defined phase of cardiac activity and is characterized by variability. Noise is increased sometimes when the stethoscope is pressed and the body tilts forward.

Quite often there are combined heart defects (two or more valves), as well as a combination of two vices of the same valve. This leads to the appearance of several noises, the exact identification of which causes difficulties. In this case, attention should be paid both to the noise level and the listening area, and to the presence of other signs of the defect of a valve, in particular, changes in heart sounds.

If there are two noises (systolic and diastolic) at the same hole at the same time, which is often enough, there is a suggestion of double damage, narrowing of the opening and insufficiency of the valves. However, in practice this assumption is not always confirmed. This is due to the fact that the second noise is often functional.

Intracardiac murmurs can be organic, ie, associated with anatomical changes in the structure of the valves, or functional, ie, appear with unchanged heart valves. In the latter case, noise is associated with fluctuations arising from a faster flow of blood, especially liquid blood, i.e., containing a smaller number of shaped elements. Such a rapid flow of blood, even in the absence of narrowed holes, causes vortices and oscillations in the intracardiac structures, which include papillary muscles and chords.

[1], [2], [3], [4], [5], [6], [7],

Functional heart murmurs

Functional noise differs from organic by a number of features. They are more variable in sonority, especially when changing position and breathing. Usually they are softer and quiet, not more than 2-3 degrees of loudness. Scraping and other gross noise is not functional.

Functional systolic murmur is quite common in children and young adults. Among the causes of functional systolic noises, associated with the acceleration of blood flow, can be called febrile states, anemia, leading to a decrease in blood viscosity and acceleration of blood flow.

Diastolic murmurs are relatively rarely functional; in particular, they occur in anemia in patients with renal insufficiency and are listened most often on the basis of the heart in the second intercostal space to the left near the edge of the sternum.

A number of physiological and pharmacological effects lead to a change in the auscultatory pattern of the heart, which can be of diagnostic significance. Thus, with a deep inhalation, the venous return of blood to the right parts of the heart increases, usually the noises appearing in the right side of the heart, often with the splitting of the second tone. With a Valsalva test (straining with a closed glottis), blood pressure decreases, the venous inflow to the heart decreases, which can lead to increased noise in obstructive cardiomyopathy (muscular subaortic stenosis) and a decrease in noise associated with aortic stenosis and mitral insufficiency. In the transition from the supine position to the standing position, the venous inflow to the heart decreases, which leads to the aforementioned changes in the auscultatory pattern in the left side of the heart. When amylnitrite is administered, blood pressure decreases, cardiac output increases, which increases noise in aortic stenosis, obstructive cardiomyopathy.

Factors that change the auscultatory picture of the heart

1. Deep breath - Increased venous return of blood to the heart and increased noise in the vices of the right heart.
2. Standing position (fast rising) - Reduction of blood return to the heart and easing of noise in stenosis of the aorta and pulmonary artery.
3. Valsalva test (straining with closed glottis) - Increased intrathoracic pressure and a decrease in venous inflow to the heart.
4. Inhalation of amyl nitrite or nitroglycerin intake - Vasodilation - enhancement of ejection noise caused by aortic or pulmonary stenosis.

[8], [9], [10], [11], [12], [13], [14]